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  • 1.
    Andersson, Anders
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Wiklund, Greger
    Påsvetsning, upplegering och ytomsmältning (glasering) med högeffektlaser1983Report (Other academic)
  • 2.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Bearbetning med högenergistrålar - RACER II: ett industristyrt program för utveckling av RAtionella bearbetningsproCessER - laserbearbetning och abrasiv vattenstråleskärning : finansierat av VINNOVA och svensk industri : sammanfattning av programmet2002Report (Other academic)
    Abstract [sv]

    Luleå tekniska universitet har tillsammans med VINNOVA drivit ett industristyrt forskningsprogram, RACER II, för utveckling av bearbetning med högenergistrålar. Programmet har genomförts genom samarbete mellan Luleå tekniska universitet, Chalmers Lindholmen, Lunds Tekniska Högskola, IVF samt 20 svenska industrier och har pågått under ca ett år med avslutning i december 2001. RACER II har varit en fortsättning på RACER, som har varit ett liknande program vilket avslutades i september 2000. RACER II har syftat till att demonstrera nya användningar av högenergistrålar i verkstadstekniska tillämpningar i laboratoriet eller implementerade i industrin; att etablera nya och innovativa former för tekniköverföring mellan forskare på högskolor i samverkan med institut, storföretag och små och medelstora företag, samt skapa en mätbart höjd kompetensnivå i forskning, utveckling och tillämpning. Inom programmet har fem projekt bedrivits varav fyra inom laserbearbetning med inriktning mot svetsning och ytbehandling samt ett inom abrasiv vattenstråleskärning. Projekten har dels gett en allmän kunskapsuppbyggnad, men delar av arbetet inom projekten har också varit direkt inriktade mot utveckling av företagens processkunnande för deras egna produkter och produktionssystem. RACER II- programmet har etablerat nya och förstärkt befintliga kontaktnät mellan universitet/högskolor, institut och svensk industri.

  • 3.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Bearbetning med högenergistrålar: RACER - ett industristyrt program för utveckling av RAtionella bearbetningsproCessER - laserbearbetning och abrasiv vattenstråleskärning2000Report (Other academic)
    Abstract [sv]

    Luleå tekniska universitet har tillsammans med NUTEK drivit ett industristyrt forskningsprogram, RACER, för utveckling av bearbetning med högenergistrålar. Programmet har genomförts genom samarbete mellan Luleå tekniska universitet, Chalmers Lindholmen, Lunds Tekniska Högskola, IVF samt ett 20-tal svenska industrier och har pågått under två år med avslutning i september 2000. RACER har syftat till att demonstrera nya användningar av högenergistrålar i verkstadstekniska tillämpningar i laboratoriet eller implementerade i industrin; att etablera nya och innovativa former för tekniköverföring mellan forskare på högskolor i samverkan med institut, storföretag och små och medelstora företag samt skapa en mätbart höjd kompetensnivå i forskning, utveckling och tillämpning. Inom programmet har sju projekt bedrivits varav fyra inom laserbearbetning med inriktning mot svetsning och ytbehandling och tre inom abrasiv vattenstråleskärning. Projekten har dels gett en allmän kunskapsuppbyggnad men delar av arbetet inom vissa projekt har också varit direkt inriktade mot utveckling av företagens processkunnande för deras egna produkter och produktionssystem. Programmet har utvecklat teknikområdet och skapat en snabb och direkt tekniköverföring till deltagande företag och snabb teknikspridning till andra företag genom programkonferenser, publikationer i vetenskaplig och populärvetenskaplig press samt via Internet där delresultat och rapporter har publicerats under programmets gång. Ett flertal demonstratorer i form laserbearbetade produkter och nyutvecklad utrustning implementerade i laboratorier har också utvecklats. Flera av de deltagande företagen fortsätter nu utvecklingsarbetet inom området i en fristående fortsättning av programmet - RACER II.

  • 4.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Euroblech 2002: högautomatisk laserbearbetning2003In: Verkstäderna, ISSN 1651-0682, no 1, p. 18-20, 22Article in journal (Other academic)
  • 5.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Laser cladding by powder injection1990Report (Other academic)
  • 6.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Laser welding catalytic converters: a complete success for AP Torsmaskiner AB, Sweden1999In: Svetsaren, ISSN 0039-7083, Vol. 54, no 1-2, p. 26-28Article in journal (Other academic)
    Abstract [en]

    AP Torsmaskiner AB (Smaland, Sweden) is using an LMI laser welding machine equipped with a Trumpf 6 kW CO2 turbolaser and a helium shielding gas for welding car catalytic converters. The LMI system has three axes with two welding stations, with the laser being switched between stations via a moving indexing mirror. The silencer/catalytic converter is produced from W-1.4512 ferritic stainless steel using lap joints. Commissioning problems, including porosity due to dry oil from pressing steel plates, are discussed. Potential system design improvements are mentioned.

  • 7.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Påsvetsning med högeffektlaser1986Report (Other academic)
  • 8.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    "Racer": a new laser and water jet R&D programme in Sweden1999In: 7th NOLAMP Conference: 7th Nordic Conference on Laser Processing of Materials ; [Lappeenranta, 1999] / [ed] Veli Kujanpää; John Ion, Lappeenranta: Lappeenrannan teknillinen korkeakoulu , 1999, p. 48-50Conference paper (Refereed)
    Abstract [en]

    A new research and development programme, called Racer, for the promotion of laser and water jet technologies in mechanical engineering industries in Sweden is described. The programme is financed mainly by NUTEK, the Swedish National Board for Technical and Industrial Development. The programme is supported by more than 20 Swedish companies with Lulea University of Technology acting as programme manager. The sub-projects are: development of laser welding techniques for components of thick engineering materials; automation and laser welding by industrial robots; development of process technology and production equipment for laser surface treatment; laser surface hardening by Nd:YAG and diode lasers; and the development of alternative process technology for abrasive water jet cutting.

  • 9.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    RACER ger industrin ny kunskap om laser och om vattenstråleskärning2002In: Svetsen, ISSN 0039-7091, no 3, p. 7-9Article in journal (Other academic)
    Abstract [sv]

    Sammanfattning av delprojekt i ett industridrivet program, finansierat av VINNOVA och ett 25-tal deltagande företag

  • 10.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Theoretical and practical aspects of laser cladding1996Licentiate thesis, comprehensive summary (Other academic)
  • 11.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Ilar, Torbjörn
    Flexibla tillverkningssystem med högeffektslaser1987Report (Other academic)
  • 12.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Ivarsson, Anders
    Luleå tekniska universitet.
    Programstyrd metodväxling vid laserbearbetning1989Report (Other academic)
  • 13. Engström, Hans
    et al.
    Kaplan, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Adaptive process control in laser robotic welding2003In: 9th NOLAMP Conference: 9th Conference on Laser Materials Processing in the Nordic Countries ; 4 - 6 August 2003, [Trondheim] / [ed] Einar Halmøy, Trondheim: Department of Geography, Norwegian University of Science and Technology, 2003, p. 251-258Conference paper (Refereed)
    Abstract [en]

    An adaptive process control and seam tracking system for robotic laser welding with filler was developed and then evaluated for the butt welding of SS-1147 mild steel sheets of thickness 2 mm. The system comprises a 3 kW Nd:YAG laser, an industrial robot and a laser camera for seam tracking and measurement of gap width. The gap width data are used to control welding speed and wire feed rate. Experiments were carried out to weld butt joints of SS-1147 mild steel with gap widths varying between 0-0.8 mm. The resultant weld geometry was evaluated to determine the operating range of the laser camera (measured gap width) for monitoring to result in acceptable welds.

  • 14.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Kaplan, Alexander
    Education of Industrial Users of Laser Materials Processing Technology2005In: 10th NOLAMP Conference: the 10th Nordic Laser Materials Processing Conference, 17-19 August 2005, Luleå Sweden / [ed] Alexander Kaplan, Luleå: Luleå tekniska universitet, 2005, p. 33-40Conference paper (Refereed)
    Abstract [en]

    The extensive use of high power laser for materials processing in industry has brought a new era in manufacturing technology. High speed processing with low heat input and high precision offers up-to-date manufacturing. New processes like laser hybrid welding are developed and introduced in industry. But the potential of laser technology is not by far fully utilised due to lack of knowledge of laser processes in the industrial environment.The national Swedish programme, "proDesign - Expert competence in industrial product development and materials processing", offers new opportunities of providing education for industrial managers, designers and manufacturing people. Within the scope of proDesign, Luleå University of Technology has developed several new courses in laser material processing for people in industry. These courses have now uccessfully been introduced to the Swedish market and this paper presents experiences from this work.

  • 15.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Kaplan, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    New laser projects to strengthen the manufacturing industry in northern Scandinavia2011In: 13th NOLAMP Conference: 13th Conference on Laser Materials Processing in the Nordic Countries 27 - 29 June 2011 / [ed] Einar Halmøy, Department of Geography, Norwegian University of Science and Technology, 2011Conference paper (Refereed)
    Abstract [en]

    The industrial development in northern part of Scandinavia has for the last years steadily beengrowing, primarily driven by strong expansion in mining, hydro power and wind powerindustries, which influences the growth and also demand on the mechanical industry in thearea. In order to further develop the competitiveness of manufacturing companies and thepromotion of laser technology in the north of Sweden and Finland, three new laser projectswere approved. These projects will be presented in this paper.. One project at LuleåUniversity of Technology (LTU) will support industry to develop and implement lasers inmanufacturing, combined with further development of an interesting laser process useful forthe regional industry. One project is a cooperation project between LTU and University ofOulu that will focus on developing optimal laser welds in high strength steels using highpower fibre- and disc lasers and evaluation of fatigue properties of the welds. The thirdproject deals with fatigue properties of laser clad surfaces and is a cooperation projectbetween LTU and Centria Research unit of Central Osterbothnia of Applies Sciences,involving also Tampere University of Technology.

  • 16.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Magnusson, Claes
    High power laser materials processing in the nordic countries1997In: Proceedings of the 6th Nordic Laser Material Processing Conference, Luleå, Sweden, August 27-29, 1997 / [ed] Claes Magnusson; Hans Engström, Luleå: Luleå tekniska universitet, 1997, p. 6-8Conference paper (Refereed)
  • 17.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Magnusson, Claes
    Sarady, Istvan
    Mätning av yttemperaturen hos transmissiv optik vid laserbearbetning1990Report (Other academic)
  • 18.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Nilsson, Klas
    Luleå tekniska universitet.
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Nilsson, Tony
    SSAB Tunnplåt AB.
    Skirfors, Anders
    SSAB Oxelösund AB.
    Gustavsson, B.
    Laser hybrid welding of high strength steels2001In: Congress proceedings: Laser Materials Processing Conference; Laser Microfabrication Conference [at] ICALEO 2001, 20th International Congress on Applications of Lasers & Electro-Optics : October 15 - 18, 2001, Adam's Mark Hotel, Jacksonville, Florida, USA / [ed] Xiangli Chen, Orlando, Fla.: Laser institute of America , 2001, p. 125-134Conference paper (Refereed)
    Abstract [en]

    This paper presents results from an ongoing investigation into laser-arc-hybrid welding of thick, high strength steels used in the heavy mechanical and heavy automotive industries. The results include welding parameters for a 6 and 12 kW laser combined with conventional MIG/MAG equipment. In this work, the laser-arc-hybrid welding technique has been further developed and applied to thick steel plate welding, giving high quality welds at high speeds. Successful welds were obtained on 6-12 mm plate thickness with laser, plasma or sheared edges as received from the blanking process. Thereby any costly, additional joint preparation is avoided, giving the hybrid welding technique an enhanced potential for use in the heavy automotive and mechanical industries

  • 19.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Nilsson, Klas
    Luleå tekniska universitet.
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Nilsson, Tony
    SSAB Tunnplåt AB.
    Skirfors, Anders
    SSAB Oxelösund AB.
    Miller, Marcus
    Volvo Aritculated Haulers AB.
    High power laser welding of thick construction steels2000In: Proceedings of the Laser Materials Processing Conference.: [November 15 - 18, 1999, Catamaran Resort Hotel, San Diego, CA, USA] / [ed] Paul Denney, Orlando, Fla: Laser institute of America , 2000, p. A42-A51Conference paper (Refereed)
    Abstract [en]

    Experimental results are reported from an investigation to develop a laser welding technique for welding thick (greater than 5 mm) construction steels. The construction steels investigated were: three grades of high strength Domex steels (6-8 mm thickness), high strength Weldox 500 (6 mm thickness) and wear resistant Hardox 400 (10-15 mm thickness). The following tests were performed to evaluate the laser welded joints: visual inspection, radiographic examination, macrophotographs, hardness, bending and tensile tests, and impact toughness tests. Three types of joint were studied: autogenous butt joints, filler welded butt joints and corner joints. Design opportunities for this process are also discussed.

  • 20.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Nilsson, Klas
    Luleå tekniska universitet.
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Nilsson, Tony
    SSAB Tunnplåt AB.
    Skirfors, Anders
    SSAB Oxelösund AB.
    Miller, Marcus
    Volvo Aritculated Haulers AB.
    Lasersvetsning av tjockt konstruktionsstål: ny svetsteknik på frammarsch för den tyngre industrin2000In: Svetsen, ISSN 0039-7091, no 1, p. 5-10Article in journal (Other academic)
  • 21.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Nilsson, Klas
    Luleå tekniska universitet.
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Nilsson, Tony
    Luleå tekniska universitet.
    Skirfors, Anders
    Miller, Marcus
    Sandqvist, Erik
    Utveckling av lasersvetsteknik för detaljer i tjockt konstruktionsstål: ett projekt inom RACER - ett industristyrt utvecklingsprogram för laserbearbetning av abrasiv vattenstråleskärning2000Report (Other academic)
    Abstract [sv]

    Svetsning med högeffektslaser erbjuder många fördelar jämfört med konventionella svetsmetoder; hög svetshastighet, låg eller oftast ingen förbrukning av tillsatsmaterial, lätt automatiserad, mycket hög svetskvalitet och framför allt liten värmepåverkan med liten, vanligen försumbar, formändring av arbetsstycket. CO2-lasrar med uteffekter på 20 kW samt den snabba utvecklingen av högeffekts Nd:YAG-laser kombinerad med fiberoptik erbjuder potentiellt stora utvecklingsmöjligheter för industriell användning inom området svetsning av tjocka material. F&U inom området lasersvetsning av tjock plåt pågår i Europa och är främst riktad mot varvsindustrin. I Sverige har ett initiativ tagits för att introducera tekniken hos tung fordons- och verkstadsindustri. Målet med projektet, som finansierats av NUTEK och deltagande projektpartners från industrin, har varit att vidareutveckla tekniken att lasersvetsa höghållfasta konstruktionsstål och introducera tekniken till i första hand tung fordons- och verkstadsindustri. Projektet har omfattat F&U av lasersvetsning av tjock plåt 8 - 15 mm i hållfasthetsområdet 280 - 960 MPa . Verkstadsindustriföretag och ståltillverkare har aktivt deltagit i projektet. Mekanisk hållfasthetsprovning och metallografiska studier av utförda svetsar har visat på mycket goda resultat i de flesta fall bättre än med konventionella svetsmetoder. Fortsatta försök med svetsade lådbalkar som tidigare provats avseende statisk hållfasthet och utmattningshållfasthet har uppvisat testresultat som överträffar de som svetsats med konventionella metoder. Svetsresultaten visar att lasersvetsning ger produktionsmässiga parameterfönster upp till plåttjocklek = 10 mm för de undersökta stålen. Från 12 mm och uppåt är resultaten hittills inte helt entydiga varför fortsatt utvecklingsarbete krävs för att öka förståelsen hos processen och för att vidareutveckla tekniken.

  • 22.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Nilsson, Klas
    Luleå tekniska universitet.
    Nilsson, Tony
    Luleå tekniska universitet.
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Skirfors, Anders
    SSAB Oxelösund AB.
    Miller, Marcus
    Volvo Aritculated Haulers AB.
    Laser welding of thick structural steels2001In: 8th NOLAMP, Proceedings: 8th Nordic Conference on Laser Materials Processing, 13th-15th August 2001 / [ed] F.O. Olsen; J.K. Kristensen, Lyngby: Technical University of Denmark , 2001, p. 93-104Conference paper (Refereed)
    Abstract [en]

    Experiments to determine process conditions for laser welding of thick structural steels are reported. Materials tested were: Domex 355, 460, 600 and 390, high strength, cold forming, microalloyed steels, 8-12 mm thickness; Weldox 960 high strength structural steel, 10 mm thickness; and Hardox 400 wear resistant steel, 10-15 mm thickness. Tests were performed using 12 and 17 kW lasers, with milled or laser cut edge preparation, various butt joint preparations, using autogenous and filler wire welding. Weld shape, microstructure and hardness, torsion fatigue strength, process envelopes for avoidance of solidification defects and laser optics requirements are reported.

  • 23. Engström, Hans
    et al.
    Norman, Peter
    Kaplan, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    DATLAS: a new approach for monitoring the laser welding process2007In: 11th NOLAMP Conference: 11th NOLAMP Conference in Laser Processing of Materials ; Lappeenranta, August 20 - 22,2007 / [ed] Veli Kujanpää, Lappeenranta: Lappeenranta University of Technology Press, 2007Conference paper (Refereed)
  • 24.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Norman, Peter
    Karlsson, Jan
    Hybridsvetsning av lastbilskomponenter med 15 kW fiberlaser och MAG2010Report (Other academic)
  • 25.
    Engström, Hans
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Wiklund, Greger
    Mårtensson, Bertil
    Robotiserad lasersvetsning: ett delprojekt inom RACER II - ett industristyrt utvecklingsprogram för laserbearbetning och abrasiv vattenstråleskärning2001Report (Other academic)
    Abstract [sv]

    Kombinationen laser industrirobot har utvecklats till ett effektivt system för industriell produktion. Idag används till största delen Nd:YAG-laser tillsammans med olika industrirobotar för svetsning och skärning. Lasersvetsning med industrirobot inom bilindustrin utförs typisk på takkonstruktioner och huvar/bakluckor vilka till sin natur är enkla svetsgeometrier med relativt raka svetsar som normalt inte kräver komplicerade robotrörelser. Svetsning av överlappsfog dominerar. Denna fogtyp ställer betydligt mindre krav på toleranser på ingående komponenter samt noggrannhet hos laser/robot systemet än svetsning av stumfog. Målet med projektet är att hämta hem och vidareutveckla teknik för att kunna utföra och demonstrera avancerad robotiserad lasersvetsning, samt effektivt överföra denna kunskap till de industriella projektdeltagarna och övrig svensk industri. Projektet syftar också att lösa svetstekniska problem vid svetsning av svårsvetsade material som ferritiska Cr-stål och härdat specialstål, samt att svetsa industriella applikationer. Projektdeltagare har varit Faurecia Exhaust Systems AB, Motoman Robotics Europe AB och Hägglunds Vehicle AB. I projektet har vi utvecklat teknik för fogföljning och adaptiv styrning av svetsprocessen vid robotiserad lasersvetsning. Systemet har testats med bra svetsresultat för varierande spalter upp till 0.75 mm i 2 mm tjock stålplåt. Kallvalsad plåtyta med frästa kanter kräver en spalt på ca 0.15 mm för att fogföljaren ska kunna detektera spalten. Detta är det första adaptiva systemet i världen som har satts i drift av Motoman. Svetteknik har undersökts och utvecklats för ARMOX 500. Med lämplig eftervärmning erhålls svetsar av hög kvalitet med goda mekaniska hållfasthetsegenskaper. Svetsteknik har också utvecklats för 17% Cr-stål. För plåttjocklek 3 mm blir svetshastigheten med Nd:YAG-laser begränsad till ca 2 m/min, där högre hastigheter ger kraftiga genomrinningar. Porförekomsten kan elimineras genom att använda dubbelfokusoptik och nitrogen som skyddsgas men Faurecia Exhaust Systems AB menar att denna gas inte bör användas på grund av ökad risk för interkristallin korrosion samt att duktiliteten kan försämras. Även svetsteknik för en rör-fläns applikation där röret består av 17% Cr-stål och flänsen av ett C-Mn stål har utvecklats. Sprickbildning i svetsgodset har dock inte kunnat undvikas.

  • 26.
    Engström, Robert
    et al.
    Luleå tekniska universitet.
    Magnusson, Claes
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Flexibla laserbaserade produktionsceller1991Report (Other academic)
  • 27.
    Flinkfeldt, Jan
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Lindgren, Bertil
    Luleå tekniska universitet.
    Laserbehandling av verktyg: state of the art 19981999Report (Other academic)
  • 28.
    Forsman, Tomas
    et al.
    Luleå tekniska universitet.
    Lampa, Conny
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    The Luleå model for laser welding simulation2001Report (Other academic)
    Abstract [en]

    Laser welding is emerging as one of the most interesting methods for joining of metals. The process has already been proven in both high quality welding in aerospace, electronics and medical engineering as well as in applications for high volume production in automotive industry. Over the past decade a substantial amount of theoretical research has been carried out into the subject of deep penetration laser welding. Many of the models developed for the laser welding process, are highly sophisticated and demand the work of scientists for performing the modelling and interpretation of the modelling results. There is a substantial lack of "easy-to-use" models which can be handled by research and development engineers in the manufacturing industry and which will give such important data as the geometrical size and form of the welded joints. The over all objective by this work was to develop a fast and user-friendly model for the prediction of weld geometries in various engineering materials, different joint types and wavelengths in laser welding. A basic, analytical thermodynamic model, first developed by A. Kaplan and then further by C. Lampa, was expected to be a suitable base for continuing development of a laser welding model, which could be used for real joint configurations and various engineering materials, as well as for both CO2- and Nd:YAG-lasers. The project has succeeded in developing this analytical model, "The Luleå model for laser welding simulation", for predicting the geometrical dimensions of laser welds in overlap and butt configuration. The metals supported by the model are mild steels, stainless steels, aluminium alloys and titanium alloys. Welding of those materials can be simulated by using CO2- or Nd:YAG laser. A PhD-degree and a substantial amount of scientific results for a docent degree have also been achieved by this work. The analytical model has been given a user-friendly interface and is incorporated on a CD for easy access. Through the software interface, the material properties and process parameters can be changed to the liking of the user. Calculated results in form of weld shape as a function of process speed are offered and compared to experimental macrographs. The "Luleå model for laser welding simulation", was in its basic state originally developed for ELANET, the "EuroLaser Academy Network for Educational Tools". The objective of the ELANET is to make use of the numerous theoretical investigations in laser materials processing carried out in the past. Developed models, including "the Luleå model" shall be implemented into a CD for easy accessibility and distribution. The simple structure of the calculation logic of this analytical model does not require high performance computer sources. The "Luleå model for laser welding simulation" is therefore suitable for use directly on a shop floor on a standard equipped personal computer. The introduction and implementation of the model to the industry is planned to take place during year 2001 when the model will be presented and used in practical industrial tests.

  • 29.
    Gedda, Hans
    et al.
    Luleå tekniska universitet.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Wahlström, G.
    Li, W-B
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Magnusson, Claes
    Energy redistribution during CO2 laser cladding2001In: Congress proceedings: Laser Materials Processing Conference; Laser Microfabrication Conference [at] ICALEO 2001, 20th International Congress on Applications of Lasers & Electro-Optics : October 15 - 18, 2001, Adam's Mark Hotel, Jacksonville, Florida, USA / [ed] Xiangli Chen, Orlando, Fla: Laser institute of America , 2001, p. 549-558Conference paper (Refereed)
    Abstract [en]

    This paper examines the factors that effect the efficiency of the CO sub 2 -laser powder cladding process. By theoretical calculation and experimental work it has been possible to identify how much of the original laser energy contributes to the cladding process and how much is lost to the surrounding environment by reflection, radiation, convection etc. Every aspect of energy redistribution has been analysed and quantified and this has lead to a deeper understanding of the process. The paper concludes with a number of suggestions for improving the efficiency of blown powder laser cladding

  • 30.
    Gedda, Hans
    et al.
    Luleå tekniska universitet.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Wahlström, G.
    Duroc AB.
    Li, W-B
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Magnusson, Claes
    Energy redistribution during CO2 laser cladding2002In: Journal of laser applications, ISSN 1042-346X, E-ISSN 1938-1387, Vol. 14, no 2, p. 78-82Article in journal (Refereed)
    Abstract [en]

    This article examines the factors that effect the efficiency of the CO sub 2 -laser powder cladding process. By theoretical calculation and experimental work it has been possible to identify how much of the original laser energy contributes to the cladding process and how much is lost to the surrounding environment by reflection, radiation, convection, etc. Every aspect of energy redistribution has been analyzed and quantified and this has led to a deeper understanding of the process. The article concludes with a number of suggestions for improving the efficiency of blown powder laser cladding.

  • 31.
    Håkansson, Anders
    et al.
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Abrahamsson, Lena
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Human Work Science.
    Kaplan, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Määttä, Antti
    University of Oulu.
    Mäntyjärvi, Kari
    University of Oulu.
    Barriers to implementation of laser welding technology: A study of 11 companies in Scandinavia2015In: Manufacturing Science and Technology, ISSN 2333-2735, Vol. 3, no 2, p. 48-55Article in journal (Refereed)
  • 32.
    Kaplan, Alexander
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Håkansson, Anders
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Innovation and Design.
    Engström, Hans
    Projekt: Forum för Industriell Framtid2013Other (Other (popular science, discussion, etc.))
    Abstract [sv]

    För att uppnå det övergripande målet att skapa en internationellt konkurrenskraftig regional tillverkningsindustri har projektet följande mål: • Genomföra ett antal högkvalitativa seminarier där experter möter små eller medelstora svenska och finska företag. Seminarierna ska resultera i en ”Agenda för industriell framtid” • Implementera ett antal demonstranter (svetsning) där man kan utveckla och träna operatörer, utveckla nya organisationsformer, testa olika styrsystem, samordna demonstratorer i nätverk och ett antal andra aktiviteter som utvecklats inom ”Agenda för industriell framtid” • Genomföra 20 handlingsprogram (ett för varje företag) där man försöker realisera agendan i anslutning till den etablerade demonstratorn. Målsättningen är att förbättra det ekonomiska omsättningen med 15 % samtidigt som man förbättrar miljön med 15 %. • Arrangera ett internationellt slutseminarium Projektets vision är att regionens tillverkningsindustri kan ses som en av de mest avancerade SME-kulturerna i världen. Baserat på avancerad hög-teknologi lyckas man utveckla innovativa produkter i världsklass, samtidigt som man värnar om ekologisk hållbarhet. Metoder för jämställdhet, som bidrar till att bryta den sneda könsfördelningen inom industrin, har utvecklats. Företagen är konkurrenskraftiga och genererar såväl höga intäkter som en stabilt växande arbetsmarknad.

  • 33.
    Li, W-B
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Tan, Z.
    Magnusson, Claes
    Modeling of the laser cladding process: preheating of the blown powder material1995In: Lasers in engineering (Print), ISSN 0898-1507, E-ISSN 1029-029X, Vol. 4, no 4, p. 329-341Article in journal (Refereed)
    Abstract [en]

    Laser cladding is a high precision method of improving the wear and corrosion resistance of metal surfaces. The process gives high quality, porosity free surface layers, with low dilution of the substrate material and with excellent bonding to the substrate. Most frequently metal powder is used as cladding material and there are basically two different methods of application: i) a pre-placed bed of powder on the substrate surface; ii) powder blown into the beam-substrate interaction zone by an inert gas stream, The blown powder cladding process is much more flexible with respect to surface geometries and is therefore the most frequently used method in industry and the subject of this paper. As the blown particles travel through the laser beam on their way to the laser-substrate interaction zone they become heated. This paper gives the results of a theoretical model which investigates the level of pre heating experienced by the particles and the effects of various parameters on this pre heating. The results are important, as the powder particle temperature is expected to be an important parameter in the modelling and control of the cladding process.

  • 34.
    Li, W.-B
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Tan, Z.
    Magnusson, Claes
    Redistribution of the beam power in laser cladding by powder injection1996In: Lasers in engineering (Print), ISSN 0898-1507, E-ISSN 1029-029X, Vol. 5, no 3, p. 175-183Article in journal (Refereed)
    Abstract [en]

    In the process of cladding by using blown powder, the laser light passes through the injected powder and is incident on the surface of the substrate. As a result of the presence of the powder cloud there will be a reduction in the laser beam irradiance experienced by the melt pool below it. This effect will be more pronounced where the cloud is at it's deepest. The original laser power density distribution will therefore be altered by passage through the powder stream. The present paper quantitatively describes this phenomenon and suggest some equations by which the redistribution of the power density of the laser beam through the powder cloud can be evaluated. The significance of the redistribution of the laser beam and its possible effect on the temperature in the substrate is also discussed.

  • 35.
    Ljung, Anders
    et al.
    Luleå tekniska universitet.
    Bengtsson, Bo
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Johansson, Anja
    Luleå tekniska universitet.
    Nilsson, Klas
    Luleå tekniska universitet.
    Wiklund, Greger
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Laserhandbok: bearbetningsteknik och bearbetningsmetoder med CO2-laser1983Report (Other academic)
  • 36.
    Nilsson, Klas
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Flinkfeldt, Jan
    Luleå tekniska universitet.
    Utveckling av laserhybridsvetsning för detaljer av tjockt konstruktionsstål2001Report (Other academic)
    Abstract [sv]

    Lasersvetsning har utvecklas till en sammanfogningsmetod av intresse även för tung industri. Autogen lasersvetsning av plåt >10 mm tjocklek medför dock ofta problem i form av varmsprickbildning samt att fogspalter kan orsaka oacceptabla svetsdiken. Laserhybridsvetsning, som är en ny metod, kombinerar lasersvetsning med konventionell MIG/MAG-svetsning och ger fördelar främst genom förmåga att fylla fogspalter och ger även ökad produktivitet. Laserhybridmetoden ger också låg sträckenergi jämfört med konventionell MAG-svetsning. Målet med projektet har varit att skapa förbättrade tekniska förutsättningar för att underlätta införandet av lasersvetsning av tjockt konstruktionsstål i industriella tillämpningar. I projektet har laserhybridsvetsteknik vidareutvecklats för utvalda kallformnings- och konstruktionsstål i tjocklekar 6-12 mm. Klippta, laserskurna och plasmaskurna ämnen har svetsats, utan ytterligare kostnadskrävande mekanisk fogberedning, med bra svetsresultat avseende svetsgeometri och mekanisk hållfasthet. Hybridsvetsning har befunnits relativt okänslig för olika typer av processgaser men en blandning av He/Ar/Co2 kan användas i de flesta fall. Applikationer och delmoment i applikationer har svetsats och utvärderats samt de ekonomiska förutsättningarna för laserhybridsvetsning studerats. Projektet ingår i ett nationellt forskningsprogram, RACER II, där teknik utvecklasför laserbearbetning och abrasiv vattenskärning. Projektdeltagare från industrin har varit Volvo Articulated Haulers AB, Ferruform AB, SSAB Tunnplåt AB, SSAB Oxelösund AB, AGA AB och ESAB AB. Projektet har finansierats till lika delar av deltagande företag och VINNOVA.

  • 37.
    Nilsson, Klas
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Heimbs, Sebastian
    University of Kaiserslautern.
    Kaplan, Alexander
    Parameter Influence in CO2-laser/MIG Hybrid Welding2003In: 56th Annual assembly of International Institute of Welding, 2003, Vol. IIW Doc. IV-843-03Conference paper (Refereed)
    Abstract [en]

    Hybrid welding, as the combination of laser beam and arc welding, is an innovative joining technology that has many advantages compared to the single processes. With the hybrid process joint gap can overbridges and hence additional and costly joint preparation can be avoided. Also the weld metal composition can be controlled by the filler wire. The laser/MIG hybrid welding pårocess is up to 50 % faster compare to autogenous laser welding. This paper presents results from an ongoing investigation into laser/MIG hybrid welding of 6 mm thick, high strength steels.The results include welding parameters for a 6 kW CO2-laser combined with conventional pulsed MIG/MAG equipment. The influences of the basic MIG parameters as the voltage, pulsing time and pulsing frequency on the welding result were investigated, where especially the geometry of the weld seams as well as undercut formation is considered. The influence of the welding result by adjusting the lateral position of laser beam and MIG arc was also examined as well as suitable parameter setup for different joint configurations like V- and butt joints. In the case of butt joint, the maximum bridgeable gap width was determined.It was found that the MIG power has a major influence at the weld geometry. A high MIG power leads to increased undercut size and increased porosity. The variation of the lateral displacement of the MIG arc was shown to be tolerant. It can be stated that a variation of the lateral displacement of 1.5 mm gave still acceptable welding results. It was possible to weld butt joints with a gap of up to 2.0 mm and a maximum in welding speed was reached with a gap of 1.0 mm.

  • 38.
    Nilsson, Klas
    et al.
    Luleå tekniska universitet.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Kaplan, Alexander
    Influence of butt and T-joint preparation in laser arc hybrid welding2002Conference paper (Refereed)
    Abstract [en]

    Using a hybrid CO2 laser/MAG welding process, the weldability of butt and T joints (fillet welds) in mild steel (0.056%C, 0.61%Mn) plate of 8 mm thickness, as received from laser or mechanical cutting, was investigated. A 6 or 17 kW laser was used in conjunction with a conventional MIG/MAG welding gun and a mixture of helium and argon with carbon dioxide or oxygen as the shielding gas. Ranges of welding speeds, wire feed rates, stick out, welding current and voltages, arc to laser beam distances, and shielding gas compositions were used. The welds were assessed by appearance and shape, and by measurements of tensile, impact and bending properties

  • 39.
    Nilsson, Klas
    et al.
    Luleå tekniska universitet.
    Under, J.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Powell, John
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Fatigue strength of Nd:YAG-laser welded stainless steel lap joints2001In: Congress proceedings: Laser Materials Processing Conference; Laser Microfabrication Conference [at] ICALEO 2001, 20th International Congress on Applications of Lasers & Electro-Optics : October 15 - 18, 2001, Adam's Mark Hotel, Jacksonville, Florida, USA / [ed] Xiangli Chen, Orlando, Fla: Laser institute of America , 2001, p. 419-428Conference paper (Refereed)
    Abstract [en]

    The primary field of application for thin section stainless steels has traditionally been to provide a corrosion resistant surface. More recent applications of these materials have also concentrated on structural applications and there is an increasing demand for data concerning the properties of welds. Laser welding is ideally suited to the joining of thin section stainless steel sheets and this paper presents the results of an investigation into the fatigue properties of such welds. The work investigates the influence of sheet thickness, weld width, porosity and inter-sheet gaps on the fatigue life of the welds. Fatigue tests were carried out on thin section stainless steel lap welds produced by Nd:YAG-laser. Analysis of the fatigue tests results and the fracture surfaces identified sheet thickness and inter sheet gaps as having considerable effect on fatigue life. Weld width has a more moderate influence on fatigue life and weld porosity has a negligible effect at low concentrations.

  • 40.
    Norman, Peter
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Engström, Hans
    Gren, Per
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Kaplan, Alexander
    Correlation between photodiode monitoring and high speed imaging of the dynamics causing laser welding defects2008In: Congress proceedings: ICALEO, 27th International Congress on Applications of Lasers and Electro-Optics : October 20 - 23, 2008 Pechanga Resort & Casino, Temecula, CA, USA ; [includes] Laser Materials Processing Conference, Laser Microprocessing Conference, Nanomanufacturing Conference / [ed] Yongfeng Lu, Orlando, Fla: Laser institute of America , 2008, p. 829-837Conference paper (Refereed)
    Abstract [en]

    Today merely a few monitoring systems for in-process detection of laser welding defects are commercially available. Despite a trend towards cameras, industrially more robust is still a photodiode, measuring in an optically filtered spectral window either the thermal emissions from the melt and vapour or the laser beam reflections. The monitoring rule for each application is identified empirically through correlations between the signal dynamics and welding defects, as the linking mechanism is non-trivial and therefore hardly understood. Thus the method does not provide a systematic guideline to detect a certain welding defect.The here presented approach studies the context between the photodiode signal, the welding defects and the vapour, melt pool, keyhole and temperature dynamics. Simultaneous laser-illuminated high speed imaging is compared to photodiode monitoring at three spectral windows in order to identify through simultaneous timing any linking dynamics in a qualitative manner. Supportive methods are emission modelling and thermal imaging. Several cases of joints, materials and defects were studied to develop an illustrated theoretical description of the defect-signal correlations.

  • 41.
    Norman, Peter
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Engström, Hans
    Kaplan, Alexander
    State-of-the-art of monitoring and imaging of laser welding defects2007In: 11th NOLAMP Conference :: 11th NOLAMP Conference in Laser Processing of Materials ; Lappeenranta, August 20 - 22, 2007 / [ed] Veli Kujanpää, Lappeenranta: Lappeenranta University of Technology Press, 2007Conference paper (Refereed)
  • 42. Norman, Peter
    et al.
    Engström, Hans
    Kaplan, Alexander
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Theoretical analysis of photodiode monitoring of laser welding defects by imaging combined with modelling2008In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 41, no 19Article in journal (Refereed)
    Abstract [en]

    On-line process monitoring of laser welding defects by detecting characteristic changes of the process emissions via photodiodes has high potential but, due to the complex process, lack of directly interpretable and thus controllable correlations. Deep analysis of the process by high speed imaging in combination with modelling enables one to discuss the correlations between the signal and the process, as was demonstrated for quasi-steady state conditions and for transient phenomena. Despite improved knowledge through the study, several uncertainties like the emissivity, the keyhole radiation characteristics and the temperature field need to be identified more accurately for a complete theoretical description of the signal causes.

  • 43.
    Norman, Peter
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Kaplan, Alexander
    Engström, Hans
    Modelling of the impact of melt surface dyanmics on a photodiode monitoring signal in laser welding2007In: Congress proceedings: 2007 ICALEO, 26th International Congress on Applications of Lasers & Electro-Optics : October 29 - November 1, 2007, Hilton in the Walt Disney World Resort, Orlando, FL, USA ; [including] Laser Materials Processing Conference, Laser Microprocessing Conference [and] Nanomanufacturing Conference / [ed] Yongfeng Lu, Laser institute of America , 2007Conference paper (Refereed)
    Abstract [en]

    Today merely a few monitoring systems for inprocess detection of laser welding defects are commercially available. Despite a trend towards cameras, the industrially most powerful concept is still a photodiode with optical filter, measuring thermal emissions from the melt surface and from the plasma or laser beam reflections. The monitoring rule for each application is identified empirically through temporal correlations between dynamic signal changes and obtained welding defects. The mechanisms behind are widely not understood. Thus the method does not provide a systematic estimation of success for identifying a certain welding defect. The here presented research approach studies the context between welding defects, the physical mechanisms behind, particularly the dynamics of melt pool, plasma and temperature field, and the photodiode signal. Numerical simulation results of the thermal emissions from the weld pool and keyhole dynamics and their non-linear conversion into a voltage signal are presented. An essential outcome is the sensitivity of the sensor signal to certain sub-mechanisms of the motion for judging under which conditions they can be monitored. Various results are discussed for simplified hypothetic cases as well as for observed weld pool dynamics of practical relevance.

  • 44.
    Powell, John
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Tan, W.K.
    Division of Manufacturing, Engineering and Operations Management, University of Nottingham.
    Maclennan, P
    V & S Scientific (London) Ltd.
    Rudd, D.
    Laser Expertise Ltd., Acorn Park Industrial Estate, Nottingham.
    Wykes, C.
    Division of Manufacturing, Engineering and Operations Management, University of Nottingham.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Laser cutting stainless steel with dual focus lenses2000In: Journal of laser applications, ISSN 1042-346X, E-ISSN 1938-1387, Vol. 12, no 6, p. 224-231Article in journal (Refereed)
    Abstract [en]

    In this article the performance of a new type of lens is compared with traditional meniscus lenses for CO sub 2 laser cutting of medium ( > 5 mm) section stainless steel. Dual Focus lenses produce two focus spots, one above the other. This type of optic was found to be capable of higher cutting speeds and better quality cuts. A phenomenological model is presented which explains the superior performance of Dual Focus lenses. The model concentrates upon the fact that during high speed cutting of medium section metals, the laser does not irradiate the lower portion of the cut zone. This lower part of the cut is heated by the melt flowing over it, which has been previously heated by the laser. This melt preheating involves narrower kerfs and higher cut speeds if a dual focus lens is used.

  • 45. Sarady, Istvan
    et al.
    Engström, Hans
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Product and Production Development.
    Rapid tooling: en förundersökning2000Report (Other academic)
    Abstract [sv]

    Rapid Prototyping-tekniken började utvecklas för över tjugofem år sedan, med "laser cladding" som bas. Man sintrade ihop pulverformig material, levererad av enkla pulversprutor, med hjälp av en delvis fokuserade laserstråle. Dessa tidiga prototyper var tämligen klumpiga, uppnådde långt ifrån full täthet och måttnoggrannheten var låg. Den egentliga snabba prototyptillverkningen fick sitt första genombrott 1986, när processen stereolitografi introducerades. Tekniken använde en blå- eller UV-laser för att av en flytande härdplast framställa fasta, tredimensionella modeller. Där laserljuset aktiverade plasten, härdade den, på andra områden förblev den flytande. Inom två år har sådana utrustning blivit kommersiellt tillgängliga. Några år senare utvecklades selektiv lasersintring, SLS av pulverformade plastmaterial, som gav mycket högre flexibilitet, samt bättre form- och måttnoggrannhet. Även här tillverkades modellerna genom att tunna skikt "staplades" på varandra. Denna teknik vidareutvecklades både i Europa och i USA för att framställa dels funktionsdugliga komponenter av metaller, sintrade till nära nog 100% densitet, dels för att framställa verktygsinsatser för formsprutning av termoplaster och gummi samt för pressgjutning av Al-legeringar för bilindustrin. Sedan 1995 används därför begreppet Rapid Tooling, eftersom det inte bara är prototyper utan även fullt användbara komponenter och verktygsinsatser som kan tillverkas. Det är framför allt två teknik för sintring av metallpulver som torde vara av intresse för Ltu: EOSINT-M, utvecklad av EOS GmbH i Tyskland, samt Directed Material Deposition Systems, DMDS, som marknadsförs av OPTOMEC Inc. i USA. EOSINT-M lämpar sig särskilt för framställning av verktygsinsatser, medan DMDS kan användas för framställning av "near net shaped" funktionsdetaljer (enstaka eller i små serier). DMDS kan även med framgång användas för att reparera tredimensionella strukturer, såsom turbinblad, ledskenor, roterande tätningar i jetmotorer och gasturbiner, axlar, mm. Därför kan dessa två teknik anses snarare komplettera varandra än att man kan beskriva dem som konkurrerande förfaranden.

  • 46. Magnusson, Claes (Editor)
    Engström, Hans (Editor)
    Proceedings of the 6th Nordic Laser Material Processing Conference, Luleå, Sweden, August 27-29, 19971997Report (Other academic)
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